Sandwich between two piece of clear adhesive backed vinyl like Mactac Seal firmly and squeeze our bubbles. Cut in the shape that fits best, leaving a small margin around the outside. Voila, place mats!

You can go to the search bar at the top-right corner of the home page and type in "mylar balloon uses" and see what comes up. I know people cut the mylar into two pieces (front and back) and use it for gift wrap. It is pretty, and durable! :)